Shared hosting is where a customer's web site is placed on the same server as many other sites, ranging from a few to hundreds or thousands. All of the sites on a shared server share the resources of the server, such as memory or processing speed.

"Overselling" is when a host places more users on a server than it can actually accommodate. The host is betting that not all the customers will use all of their resources at the same time, so they can place more users on every server. We NEVER oversells a server and in fact rarely loads a server past 50% of it's capability.